Heat exchanger



July 9, 1940.

G. T. JACOCKS HEAT EXCHANGER Filed NOV. 13, 1937 6 Sheets-Sheet l INVENTOR George 7: Jacocks ORAMFV ly 9, 1940- G. T. JACOCKS 2,207,036

HEAT EXCHANGER Filed Nov. 13, 1937 6 Sheets-Sheet 3 5 8.; T INVENTOA George TJacoc/rs BY l July 9, 1940.

G. T, JACOCKS HEAT EXCHANGER Filed Nov. 13, 1937 6 Sheets-Sheet 4 lNVE/VTOR George T Jacocks m g ro/mm y 9, 1940- G. T. JACOCKS 6 HEAT EXCHANGER Filed Nov. 13, 1937 6 Sheets-Sheet 5 Fiy. 9.

52 INVENTOR George T. Jacocks A RAHEY y 1940- e. T. JACOCKS 2,207,036

HEAT EXCHANGER Filed NOV. 13, 1937 I 6 Sheets-Sheet 6 Patented July 9, 1940 UNITED STATES PATENT OFFICE HEAT EXCHANGER Application November 13, 1937, Serial No. 174,330

7 Claims.

This invention relates to improvements in heat exchangers, more particularly of the fluid type in which one fluid is normally conducted through the interior of a series of tubes, and another fluid, in heat exchange relation, is maintained in contact with the exterior of the tubes.

One of the principal objects of my invention is to provide a heat exchanger, the tube bundle of which has a bundle wrapper so that more intimate contact and more effective control can be had between the external fluids and internal fluids in heat exchange relation, the tube bundle being removable from the shell for inspection and cleaning.

Another object of my invention is to provide internal retractable connections for the nozzles of a heat exchanger so that the connections may be broken between the nozzle and channel or nozzle and bundle wrapper without breaking any external pipe connections.

Another important object of my invention is to provide an improved bundle wrapper for a heat exchanger tube bundle in which undesired bypassing of fluids at the bafiles is eliminated and the tube bundle wrapper held more securely, and with less required clearance than heretofore.

Another object of my invention is to provide an improved channel construction for heat exchangers in which any desired multiple pass provision can be made without reducing the actual tube area, the baffle construction being of relatively great thickness to be substantially corrosion-proof.

' Further objects and advantages of my invention will appear from the following description of preferred forms of embodiment thereof, taken in connection with the attached drawings illustrative thereof, and 'in which:

Fig. l. is an elevation of a heat exchanger with parts broken away and shown in section;

Fig. 2 is a top plan view of the heat exchanger shown in Fig. 1 with a part of the cover broken away to show the internal bailies;

Fig. 3 is an enlarged vertical section taken substantially along the line 3-3 of Fig. 2, showing the shell connection;

Fig. 4 is a partial bottom view of Fig. 1 showing channel securing means;

Figs. 5 and 6 are vertical sections like Fig. 3, but showing modified forms of shell connections;

Figs. 7 and 8 are vertical sections of modified forms of channel connections;

Fig 9 is an elevation. partly in section, of a modified form of heat exchanger;

Fig. 10 is a horizontal section of the channel of a heat exchanger, showing the channel bathe,-

and

Fig. 11 is an elevation, partly in section, of another form of heat exchanger.

60 In accordance with one form of embodiment of my invention, the heat exchanger generally shown in Fig. 1, consists primarily of a shell III of substantially continuous diameter, or cross section from end to end, which is reinforced at the channel end by skirt H, such shell being sealed at the open end by the cover l2 and at the other end by the fixed tube sheet 14. The tube sheet I 4 supports the tube bundle generally indicated at I 5, such tube bundle including a plurality of tubes suitably expanded within the fixed tube sheet I4, and extending to the floating tube sheet l6 as is well known. The floating tube sheet 16 is provided with a channel spacing member I1, and a floating tube sheet cover 18 which, being spaced from the floating tube sheet I6, provides a channel for the continuous flow between the respective tubes.

The fixed tube sheet end of the heat exchanger is provided with a channel 2| having the inlet and outlet nozzles 22, which may be cast or formed integral with the channel. The channel is completed by a channel cover 23 and this is preferably detachable for inspection purposes. The intermediate pass bafiie 24, which distributes the circulating fluids into and out of the tubes, may be integral with or detachable from the channel 2|. It will be apparent with the arrangement as shown, that the heat exchanger is of two pass type on the tube side, although any other arrangement could be made by varying the position and numbers of channel bafile 24, and the form of the channel spacing member 11.

A multiple number of passes on the shell side with a continuous floating tube sheet I6 is also possible by using a bundle wrapper 21 which is adapted to closely embrace the tube bundle l5, such bundle wrapper engaging shoulders on the fixed tube sheet l4 and the floating tube sheet I6. As shown in Figure 2, the bundle wrapper is preferably a continuous sheet of metal having a lap joint 28. The multiple pass is established by a plurality of longitudinally extending baflies 30 of relatively thin metal, placed between the tube rows. In addition a plurality of lateral baffles 32 are provided and these may be ofhalfmoon or other desired configuration. Without going into the details of the baffle arrangements possible, it will be apparent that with a bundle wrapper, many forms are possible and any arrangement can be had for the desired flui course between the shell nozzles 33.

Removal of the tube bundle without breaking the external connections to the shell nozzles is accomplished by the retractable connection shown in Fig. 3. This includes a ring member 35 of saddle form which is welded substantially fluid tight to the bundle wrapper 21 around fluid opening 21a. A continuous flexible packing 36 is sealed against the shell by a ring 38 which may be internally secured to the shell by screws 48. The ring surrounds the outer margin of the opening 330 in the shell and the screws 48 project into the nozzle pad l3, thus avoiding leaks. It will be obvious that the ring 38 may be held to the shell by external screws when the internal diameter of the shell is such that the internal screws 48 cannot be conveniently used.

The packing 36 is also substantially sealed to the bundle wrapper by the thrust relieving connection, including the thrust screw 39 which is screw-threaded into ring 35 and is provided with a screw-threaded collar 40 which abuts against the ring M. The screw 39 projects through the shell and is adjustable from the outside when the sealing cap 43 is removed.

The collar 40 floats within an opening in the shell Ill, thus eliminating thrust on the bundle wrapper; nevertheless, the joint is made substantially tight by means external of the shell and bypassing of fluids outside of the bundle wrapper is substantially prevented. The slight leakage equalizes the pressure and, as fluid flow in chamber 45 is prevented, the fluid in chamber 45 serves as an insulating medium. Leakage from the shell is prevented by cap 43 engaging washer 42.

The bundle wrapper 2'! is provided with both inlet and outlet openings, only one of which has been shown, and inasmuch as such openings are merely surrounded by a suitable ring such as 35, which may be welded to it, with the ring having a plurality of threaded openings for the thrust screws 39, no particular expense is involved in its construction. Furthermore, the bundle wrapper may be of any shape to suit the shape of the tube sheets and may be of relatively thin metal as there is no material pressure to be resisted.

A preferred manner of holding the wrapper in the lapped position heretofore described, is by a series of straps 46 each having a metal sleeve l! overlapping the strap ends. When the ends of the straps are drawn tight as by a suitable tool, not shown, the sleeve M and the ends of the straps 46 are crimped or otherwise deformed for a positive and permanent tension resisting seal. The seal is permanent and as the straps are relatively thin, no interference occurs with the shell or with the rings 38 when the bundle is withdrawn. A plurality of straps are generally used and one is conveniently provided at the attachment to the tube sheets as well as at the respective lateral baffles 32 so that seepage between the lateral bafiles and the bundle wrapper 31 is substantially eliminated. It is of course to be understood that although other means for securing the bundle wrapper can be used, the deformed strap seal permits materially reduced space between the tube bundle and shell with a resulting increase in tube bundle size for any predetermined size of shell.

The sealing of the respective cover member. channel and tube sheet members to the shell is preferably accomplished by a frusto-conical form of gasket heretofore described in a co-pending application of the present inventor, filed November 3, 1937. Serial No. 172,567. These gaskets indicated at 50, are provided between the cover I2 and the ring 5| which is secured to the shell ID; between the fixed tube sheet M and the shell i0; and between the channel member 2| and fixed tube sheet It, and channel cover 23, and between the floating tube sheet cover l8 and the skirt extension 56 on the floating tube sheet [6. Each of the respective members have complementary shoulders with relatively rounded corners in which the gasket forms a seal due to the relative change of its angular relation which change causes a tightening of the gasket on the edges. When the parts are moved to a closed position by a series of adjustable screws 52, which are preferably carried by a sectional bull ring 53, interlocked at 54 to a projection of the shell ID, or in separate lugs 60, the gasket turns to a sealing position.

This sealing movement may be in the range of from approximately 30 to 40 or less when unsealed, to a sealed condition of approximately 20 to 10. The relative angularity required can bedetermined by the amount of tolerance provided and it is based on the major diameter of the gasket itself, the total movement being the difference between the cosines of the angle. As the seal is provided between the respective shoulders against which the gasket cooperates, a secondary seal can be provided between the cover l8 and the channel member 11 and between the channel member I! and the floating tube sheet I6 as by flat gaskets 51 and 58, such gaskets preventing any possible erosion of the metal.

It will be noted that the three frusto-conical gaskets 50 at the channel end are all held in position by a single series of adjustable screws 52 which is possible Without excessive size screws as the sealing pressure of the gaskets is independent of the pressure that holds the cover, channel and floating tube sheet to the shell. The toggle action of the gaskets gives a relatively high mechanical advantage which increases as the gasket is moved to its sealed position.

The gaskets are preferably somewhat softer than the shoulders with which they cooperate so that there will be some flow of metal and all crevices will be filled. The gaskets, however, are preferably of a resilient metal so that they will continuously maintain a seal and when the pressure is relieved, they will tend to return to their original shape.

The bull ring 53 extends across the bifurcated opening 59 in the shell 10, adequately holding the channel cover 23. With a bifurcated shell, the secured channel nozzles 22 and channel 2| can be removed by removing the sections of the bull ring 53 and withdrawing the channel from the shell. The bull ring permits equal spacing of the securing screws 52. one of which can be placed over the cover at the bifurcated part of the shell as clearly shown in Fig. 4. It is held in the expanded position by securing screws 52 at the split portions. I

A modified construction for maintaining the fluid tight connection between the shell inlet or outlet and the bundle wrapper. is shown in Fig. 5. As in the prior construction, the tube bundle is generally indicated at l5 and is provided with a similar bundle wrapper 21 which extends to the floating tube sheet l6. Similarly, ring 66 is suitably secured as by welding, around the opening 21a in the bundle wrapper, and a ring 38 is detachably secured to the shell It! in such a manner as to hold the packing 61 forming the retractable coupling in substantially fluid tight relation.

The abutment ring 62 is normally held within the packing 61 and is forced against the ring 66 by the adjustable screw 64. In this case, the screw 64 is directly screw threaded through the shell l0 and applies direct positive pressure which holds the packing 61 against the bundle wrapper ring 66 and prevents by-passing of fluids in any substantial quantity within the chamber 45. A cap 65 positively seals the screw 64 against shell leakage.

A still further modified form of construction is shown in Fig. 6, in which the tube bundle I is provided with a bundle wrapper 21 which, in this case, merely has an opening 21a and is not provided with a ring. A retractable coupling 19 is provided with a suitable sealing material H,

"which is forced into contact with the bundle wrapper 21 surrounding the opening 21a, and the seal is maintained by the pressure screws 13. At the same time, the coupling 19 is sealed by the gaskets 15 with the shell extension 16 to which shell nozzle 11 is detachably secured by the screws 18 and sealed by the gasket 89.

When it is desired to remove the bundle wrapper with this form of connection, the jack screws 8| which are alternated with the pressure screws 13, are turned in a manner to withdraw the coupling 19. Both the jack screws 8| and the pressure screws 13 are provided with caps 82 and 83 to prevent leakage.

Removal of the tube bundle without destroying the external nozzle connections to the channel can be accomplished by using either the retractable form of connection shown in Fig. 7 or 8. In Fig. 7, the shell 99 has the pipe nozzles 9I integrally secured thereto as by the flange 92 welded to the shell. The channel is indicated at 94 and is secured between the channel cover 95 and the fixed tube sheet 96 by the pressure screws generally indicated at 52 and lugs 69. As in the prior construction, the channel 94 is sealed with respect to the cover 95 and the fixed tube sheet 96 by a plurality of gaskets 91 of the frustoconical type.

The nozzle Si is sealed with respect to the channel 94 by a retractable sleeve or collar 98 which is held against the nozzle by the screws 99. The parts are sealed together by a plurality of gaskets I99 and IN. the former of which is between the channel 94 and the collar 98, and the latter of which is between the collar 98 and the nozzle 9|. In this construction, by the use of the frusto-conical gaskets I99 and IN, it is possible to simultaneously seal the retractable member with respect to the channel and nozzle inasmuch as the gaskets commence to seal as soon as they rotate and the seal is increased in offectiveness as the parts are drawn together.

In Fig. 8, the shell H9 is provided with a detachable nozzle II I held by the screws I I2. As in the prior form, the nozzle III is made pressure-tight with respect to the channel II4 by a form of frusto-conical gasket II5 which in this case, engages a shoulder on the nozzle III, and a shoulder on the channel H4. By tightening up on the screws H2, the gasket will be rotated in toggle fashion to set up the desired seal. The channel H4 is secured to the fixed tube sheet H6 and cover H9 by the screws 52 and lugs 69. The jack screws I29 can be used to partially retract the nozzle III and, when retracted a sufficient distance, the channel will clear the end of the nozzle. A suitable retaining member in the form of a wire I2I is provided to assist in positively withdrawing the gasket II5 to break the sea In each of these forms, external pipe connections need not be broken in order to remove the tube bundle as in Fig. "I, the connection is broken within the shell by a retractable member and in Fig. 8. the small amount of retraction necessary for the pipe connection III can be accomplished by the jack screws I29.

The retractable connections on the channel may be used to great advantage irrespective of the use of a bundle wrapper, although they are especially valuable therewith. In Fig. 9, a modified form of retractable nozzle connection is shown on the channel of a heat exchanger the shell of which is of the single pass type. In this form of embodiment of my invention, the shell I39 has the inlet and outlet nozzles I3I, and the cover I32 is sealed to the shell as by a frustoconical gasket I34 heretofore described. Adjustable screws 52 extending into detachable lugs 69, secure the parts together.

The tube bundle is generally indicated at I49, and the fixed tube sheet MI is sealed to the shell I39 by the gasket I42, and sealed to the channel I43 by the gasket I44. The channel cover I45 is sealed to the channel by the gasket I46 and is secured to the shell I39 by the screws 52, extending through similar dernountable lugs 69.

The tube bundle I49 has the floating tube sheet I59 and the floating tube sheet cover I52, which is spaced from the floating tube sheet I59 by the spacer I53, and the floating tube sheet I52 is secured relative to the floating tube sheet I59, by the screws 52 extending through the demountable lugs 69, which engage the skirt I55, projecting from the floating tube sheet I59. Gasket I56 is provided to seal the floating 'tube sheet cover I52 to the floating tube sheet I59.

As shown in Fig. 9, the channel I 43 is wholly within the shell and the shell is provided with fixed nozzles I51. Within this nozzle are movable sleeves I58 which are provided with suitable shoulders for cooperative relation with gaskets I59 and I69. These gaskets engage shoulders on the fixed nozzle I51 and the channel I93 respectively.

Movement of the retractable sleeve I58 is accomplished by screws I62 in screw threaded engagement with the interior of the fixed nozzle I51 and in abutting relation with the sleeve I58, and being adapted to engage shoulders I58a to force the sleeve into sealed position and adapted to engage shoulders I581) to retract the sleeve. In the retracted position of the sleeve, the channel and tube bundle may be freely withdrawn from the shell. Retraction is accomplished from the exterior of the shell by the screws I 62 extending through the pipe flange I63 and no pipe connections need be broken for this purpose.

A still further modified form of embodiment of my invention is shown in Fig. 11. posite view showing the retractable bundle wrapper construction heretofore shown in Fig. 6 together with the bifurcated type of shell for removal of the bundle wrapper as shown in Fig. 1. It will be noted that the reference characters are the same as in these respective two figures and they are not again described. Such construction facilitates rapid removal of the tube bundle and channel and is firmly held in a tight manner by the bull ring 53 which extends across the bifurcated or slotted portions.

Another important feature of the present in vention is the provision of the pass-baffle I65 which, as shown in Fig. 10, is conveniently integral with the channel I43, and although shown to be central of the channel, may be in any desired position dependent upon the number of passes required on the tube side. It is well known that fluids entering the tube bundle through the nozzles I51 efiect a corrosive as well as erosive action on this baflie so that one of substantial thickness is preferable. With the close spacing of the tube, as is shown in Fig. 19. this would normally close out one half of two rows of tubes This is a comfor each pass-baffle, with the result that a material portion of the tube bundle area would be lost from effective service.

I have been able to maintain the desired relatively thick pass-baffle I65 without eliminating any of the effective tubes, by milling or drilling the pass-baffle adjacent the ends of the tubes as shown at I66. By removing an arcuate portion of the pass-baflle at the end of the tubes, I can prevent all interference with the fiow of. fluids through the tubes. This can be conveniently accomplished by using the fixed tube sheet as a jig and drilling through from the top side or the pass-bafile may be milled out or otherwise cut to accomplish the same purpose. The vertical depth of the milled out portion is approximately equal to the inside diameter of the tube so that there is free flow therethrough.

It is to be understood that this form of baflle may be used either at the channel end or at the floating tube sheet end, or both, but it is of considerable importance adjacent the channel end conduits I51, because of the initial high velocity of the fluids and the direct right angle change in their direction.

It will thus be apparent that the heat exchanger can be provided with a removable tube bundle which can be removed from the shell without breaking external pipe connections. This is irrespective of whether it be provided with a bundle wrapper. In each case, the entire channel is effectively sealed within the shell but without any reduction of effective tube area as the floating tube sheet can be almost as large as the shell. All external flanges are eliminated and by using the bundle wrapper a more effective confinement of the fluids about the tubes is accomplished.

While I have shown preferred forms of embodiment of my invention, I am aware that other modifications may be made thereto and I therefore desire a broad interpretation of my invention within the scope and spirit of the description herein and of the claims appended hereinafter.

I claim:

1. In a heat exchanger, a hollow shell, a nozzle connected to said shell and communicating with the interior thereof, a hollow, fluid-receiving member mounted within said shell and having a fluid port alined with said nozzle, a sleeve movably mounted'in said nozzle with its inner end extending beyond the inner wall surface of said shell and engageable with said member about said port for establishing communication between said nozzle and member through said sleeve and port, and means associated with said nozzle and sleeve and operable to move said sleeve within said nozzle in a direction for disengaging said sleeve from said member to permit removal of said member from said shell, said nozzle having external pipe connections unaffected by said sleeve movement.

2. In a heat exchanger, a hollow shell, a nozzle connected to the side wall of said shell and com municating with the interior thereof, a hollow, fluid-receiving member mounted within said shell and having a fluid port alined with said nozzle, a sleeve movably mounted in said nozzle and adapted to have its inner end projected beyond the inner wall surface of said shell to engage said member about said port for establishing communication between said nozzle and member through said sleeve and port, compressible gaskets between said nozzle and sleeve and between the latter and said member, and means associated with said nozzle and sleeve and operable to move said sleeve in one direction within said nozzle for compressing said gaskets and in the opposite direction for disengaging said sleeve from said member to permit removal of said member from said shell, and means to externally secure a pipe to said nozzle independently of said sleeve.

3. In a heat exchanger having a hollow shell and a tube bundle mounted Within said shell including a plurality of tubes extending axially of said shell, a bundle wrapper comprising a sheet wrapped about said tube bundle so as to confine fluid circulated through the interior of said shell to close contact with the outer surfaces of said tubes, said wrapper sheet being formed with a fluid port, a fluid circulating nozzle connected to the side wall of said shell opposite the port in said wrapper, a sleeve movably mounted within said nozzle, and means associated with said nozzle and sleeve for moving the latter axially of said nozzle in one direction for engaging the inner end of said sleeve with said wrapper about said port therein and for moving it in the opposite direction within said nozzle for retracting said sleeve to a position that permits removal of said tube bundle and wrapper from said shell, and means to connect a pipe to said nozzle, irrespective pf the position of said sleeve.

4. A heat exchanger of the class described including a shell, a tube bundle within said shell, a channel for said tube bundle within said shell; said tube bundle and channel being removable from said shell, and means to connect said channel through said shell to an external fluid source; said means including a nozzle fixed to said channel and projecting through said shell, said shell being slotted adjacent said nozzle.

5. A heat exchanger as described in claim 4, in which the tube bundle is provided with a bundle wrapper, having an opening therein, said shell being provided with a fixed nozzle adjacent said opening; a retractable sleeve within said nozzle, and means to retract said sleeve without interfering with said nozzle whereby the tube bundle is clear of the shell.

6. A heat exchanger of the class described ineluding a shell, a tube bundle mounted therein; said tube bundle including a fixed tube sheet and means to seal said tube sheet with respect to the inner diameter of said shell, said tube sheet being removable from said shell, a channel for said fixed tube sheet and a fixed connection to said channel projecting through said shell; said shell being bifurcated adjacent said fixed connection whereby said channel and tube bundle may be removed from the shell.

'7. A. heat exchanger of the class described, comprising a shell, a tube bundle therein, a channel for said tube bundle, a cover for said channel, said channel being entirely within the diameter of the shell and a connection projecting from said channel through the wall of said shell, said shell being bifurcated adjacent said connection and means to secure said channel to said shell including a bull ring, said ring having adjustable means engaging the channel cover throughout its perimeter including portions between the bifurcated edges of the shell.

GEORGE T. JACOCKS. 

